Has a Factory Reset been performed?
A Lot!
Was a Factory Reset performed before and after any firmware updates then set up from scratch?
FW Update Process
Yes
Was the router working before any firmware updates?
I notice the problem after two months updating to the latest firmware
Wireless Configurations
Links>Wireless Installation Considerations and Managing Signal Congestion and Good Neighbour Policy
Ensure the default (dlink) SSID name is changed. Can be anything and not something that's already in use by any neighboring WiFi routers. Under Setup/Wireless/Manual.
Yes its unique
What wireless modes are you using?
2.4Ghz Routers only: Try single mode G or N or mixed G and N?
i already did that and it doesnt work
Channel Width set for Auto 20/40Mhz or try 20Mhz only.
it doest work too
Try setting a manual Channel to a open or unused channel. 1, 6 or 11. 11 for single mode N if the channel is clear.
still the same
What security mode are you using? Preferred security is WPA-Personal. WPA2/AES Only. Some WiFi adapters don't support AES, so you might want to try TPIK only or Auto TPIK and AES.
it doesntwork
What wireless devices do you have connected?
i only have two wireless device
Any 2.4Ghz or 5Ghz cordless house phones or WiFi APs near by?
no
Any other WiFi routers in the area? Link> Use InSSIDer to find out. How many?
only three
If you have any of these options, Try turning OFF or ON Short GI, WLAN Partition, Extra Wireless Protection and HT 20/40 Co-existence if you have it. Also testing with HT20/40Mhz Co-existence enabled will impact results as well. I prefer to use this option OFF. Recommended settings are default. Under Advanced/Advanced Wireless.
nope the problem still exist, altough i find that i dont have the option of extra wireless protection
Router Placement
Forum User - "Well I feel really dumb. After moving the router away from other electronic devices my speeds are back to normal. Just a heads up for anyone experiencing slow speeds, you might want to move it away from other electronics and see if that helps."
6" minimum safe distance between devices.
noted but still dont resolved the problem
3rd Party Security Software Configurations
Turn off all anti virus and firewall programs on PC while testing. 3rd party firewalls are not generally needed when using routers as they are effective on blocking malicious inbound traffic.
Turn off all devices accept for one wired LAN PC while testing.
Disable any downloading client software managers, i.e. Torrents or similar.
noted, not working